Functionalized polymers

ABSTRACT

A functionalized polymer of the formula 
     
       
         A—Z—X 
       
     
     where 
     A is a block of vinylaromatic monomers of 8 to 20, preferably 8 to 12, carbon atoms, 
     Z is a basic building block of a compound having sterically hindering groups and 
     X is a functionalized basic building block, 
     the degree of functionalization of the polymer being at least 65%, preferably greater than 85%, particularly preferably at least 90%, a process for its preparation, thermoplastic molding materials containing said polymer, processes for their preparation, the use for the production of moldings, and moldings containing said molding materials.

The present invention relates to a functionalized polymer of the formula

A—Z—X

where

A is a block of vinylaromatic monomers of 8 to 20, preferably 8 to 12,carbon atoms,

Z is a basic building block comprising a compound having stericallyhindering groups and

X is a functionalized basic building block,

wherein the degree of functionalization of the polymer is at least 65%,preferably greater than 85%, particularly preferably at least 90%.

The preparation of terminal anhydride-functionalized polystyrene isdescribed in Park, J. W., Barlow, and Paul “Terminal AnhydrideFunctionalization of Polystyrene”, J. Polym. Sci., Part A, PolymerChemistry, 29 (1993), 1329-1338. Styrene is subjected to anionicpolymerization, and the polystyryllithium formed is coupled directlywith trimellitic anhydride chloride (TMAC) at the end of the anionicpolymerization of styrene. The degree of functionalization of thepolymer is not more than 61% in this direct functionalization.Polystyrenes functionalized with TMAC were also obtained by reactinghydroxyl-terminated polystyrene and TMAC. In this reaction for indirectfunctionalization, degrees of functionalization of up to 85% areachieved. However, the feasibility of this process depends on theavailability of hydroxyl-terminated polymer, which is obtainable byanionic polymerization and subsequent reaction with ethylene oxide atthe end of the polymerization (R. P. Quirk and J.-J. Ma, J. Polym. Sci.Polym. Chem. Ed. 26 (1988) 2031). Polystyrenes functionalized in thismanner to can be used for the in situ formation of block copolymers inpolymer blends for compatibilization of the polymer blend components.

The indirect functionalization has the disadvantage that ethylene oxide,which is toxicologically unsafe, must be used in the process.

Reinforced blends of PPE and high impact polystyrene, which are used asmolding materials in many areas of industry, are known per se. In manyapplications, high tensile strength and flowability of the material aredecisive.

DE 31 18 629 A1 discloses molding materials of polyphenylene ethers andtoughened styrene polymers, which molding materials contain apolyorganosiloxane as a further component for imparting good flowabilityto the molding material. If these molding materials are reinforced, therigidity of the reinforced molding material is not sufficiently high forall applications.

EP-B1 0 214 400 describes resin compositions of polyphenylene etherresin and styrene resin, which additionally comprise a cyclopentadieneresin which contains a polar group, in order to improve the flowabilityof the resin composition. In this resin composition, too, the mechanicalproperties are unsatisfactory for many applications.

EP-A 0 319 833 describes reinforced thermoplastic molding materialswhich contain polyphenylene ether, a toughened styrene polymer and afurther copolymer of styrene and tert-butyl acrylate. The copolymer ofstyrene and tert-butyl acrylate serves for improving the mechanicalproperties, but the molding material has insufficient flowability.

It is an object of the present invention to provide a functionalizedpolymer of vinylaromatic monomers, the degree of functionalization beingvery high.

It is a further object of the present invention to provide afunctionalized polymer of vinylaromatic monomers, the functionalizationcomprising no ethylene oxide basic building blocks.

It is a further object of the present invention to provide a process forthe preparation of the functionalized polymers having a high degree offunctionalization.

It is a further object of the present invention to provide a process forthe preparation of the functionalized polymers having a high degree offunctionalization, the use of the toxicologically unsafe ethylene oxidebeing dispensed with.

It is a further object of the present invention to provide reinforcedthermoplastic molding materials which have high rigidity.

It is a further object of the present invention to provide reinforcedthermoplastic molding materials which have very good tensile strengthand at the same time flowability.

It is a further object of the present invention to provide thermoplasticmolding materials which have high rigidity.

It is a further object of the present invention to provide thermoplasticmolding materials which have great toughness or impact strength.

It is a further object of the present invention to provide a process forthe preparation of these (reinforced) thermoplastic molding materials.

It is a further object of the present invention to provide moldingswhich have good rigidity and tensile strength.

We have found that these and further objects are achieved by afunctionalized polymer as defined at the outset, by a process for itspreparation, by (reinforced) thermoplastic molding materials, byprocesses for their preparation and by moldings as defined in thefollowing. Preferred functionalized polymers are described as well inthe following. Uses of the functionalized polymer and of the(reinforced) thermoplastic molding materials are described as well.

Functionalized Polymer (component (a))

The novel functionalized polymer is of the formula

A—Z—X

where

A is a block of vinylaromatic monomers of 8 to 20, preferably 8 to 12,carbon atoms,

Z is a basic building block comprising a compound having stericallyhindering groups and

X is a functionalized basic building block,

wherein the degree of functionalization of the polymer is at least 65%,preferably greater than 85%, particularly preferably at least 90%.

According to the invention, the block A may be composed of one type or aplurality of types of vinylaromatic monomers, ie. may be homopolymer orcopolymer.

A group of monomers which can be used according to the invention of Acomprises styrene monomers. Styrene monomers may be unsubstituted or maybe substituted by C₁-C₁₂-alkyl, preferably C₁-C₁₄-alkyl, on the aromaticnucleus or on the vinyl group. One or more straight-chain or branchedalkyl radicals may be present as substituents. It is also possible forboth the aromatic nucleus (benzene nucleus) and the vinyl group of thestyrene monomers to be substituted.

Examples of styrenes which may be used according to the invention arestyrene, α-methylstyrene, p-methylstyrene, vinyltoluene andp-tert-butylstyrene, particularly preferably styrene.

Vinylaromatic monomers which contain a polynuclear aromatic radicalbonded to the vinyl group may also be used. A suitable radical is, forexample, naphthyl, which may be unsubstituted or alkyl-substituted asdescribed above.

Z is a basic building block of a compound having sterically hindering(bulky) groups.

The compound is preferably a vinyl monomer which is substituted bysterically hindering groups at least on a carbon atom. Preferably, thevinyl group is substituted on a carbon atom by two aromatic radicals,preferably by vinyl radicals, which in turn may be substituted by thealkyl radicals described above for the monomers of the block A andfurther substituents. For example, alkyl of, preferably, 1-4 carbonatoms which in turn may be unsubstituted or substituted as described maybe bonded to the other carbon atom of the vinyl group. According to anembodiment of the invention, the vinyl group substituted by stericallyhindering groups has a total of 14-22 carbon atoms.

Thus, the basic building block Z is preferably diaryl alkylene of 14 to22 carbon atoms, in particular 1,1-diarylethylene of the formula

where R is hydrogen or alkyl of 1 to 4 carbon atoms and Aryl is aryl of6 to 10 carbon atoms, preferably phenyl.

X is a functionalized basic building block. According to an embodimentof the invention, the functional group(s) is/are such that they can forma strong bond, in particular a covalent bond, to a reinforcing agent,preferably a glass fiber or silanized glass fiber, in a moldingmaterial, as described below for the molding materials.

The functional group by means of which the covalent bond to the basicbuilding block Z is achieved may be any desired functional groupsuitable for this purpose. It is preferably hydroxyl or halogen,preferably chlorine. The functional group X is preferably a hydrocarbongroup carrying an acid anhydride group, in particular aryl carrying anacid anhydride group. The functional group is bonded to the carbon atomwhich also carries the aryl radicals. The functional group X is ananhydride group or an acid anhydride group. The anhydride group and theacid anhydride group are preferably of 2 to 8 carbon atoms. Preferredexamples of the functional group X are the acid anhydride radicalsderived from trimellitic acid.

According to one embodiment, this functional group serves for forming astrong bond, in particular a covalent bond, to a reinforcing agent,preferably a glass fiber or silanized glass fiber in a molding material,as described below. The difunctional or polyfunctional compound of thefunctionalized basic building block X may contain, for example, OH,COOH, COOR, SH, NCO or NH₂ as this functional group. It preferablycontains an NH₂ group or an acid anhydride group, in particular thelatter.

According to an embodiment of the invention, a difunctional orpolyfunctional compound which introduces the functionalized basicbuilding block X may be of the formula

where RZ1 and RZ2 are each a hydrocarbon radical of, preferably, 1 to 10carbon atoms, and RZ1 and RZ2 together may also form a hydrocarbon ringstructure, in particular an aromatic ring, preferably a benzene ring, ora cycloalkyl ring, the two carbon atoms of the acid anhydride grouppreferably being bonded to neighboring carbon atoms of the ringstructure. Y is hydroxyl or halogen, preferably chlorine. Preferredexamples of the functionalized basic building block X are the acidanhydride radical derived from trimellitic acid, in particular in thefollowing configurations:

The 1,2-anhydride or 1,2-anhydride chloride of1,2,4-benzenetricarboxylic acid (trimellitic acid) orchloroethanoylsuccinic anhydride, chloroformylsuccinic anhydride or1-acetoxyacetyl-3,4-phthalic anhydride is preferably used as thedifunctional or polyfunctional compound introducing the basic buildingblock X, trimellitic anhydride chloride being particularly preferred.Other compounds which have both an acid anhydride function and an acidhalide or acid function may also be used according to the invention forthe preparation of the functionalized polymer.

According to an embodiment of the invention, the basic building blocks Zand X preferably contain no ethylene oxide basic building blocks whichare present in the main chain. According to the invention, the weightaverage molecular weight of the functionalized polymer is preferablyfrom 10,000 to 300,000, in particular from 20,000 to 100,000. Themolecular weight is determined with the aid of gel permeationchromatography against polystyrene calibration standards.

The degree of functionalization of the functionalized polymer isdetermined by ¹H-NMR, but may also be determined by potentiometry or bytitration against bases using suitable indicators.

Preparation of the Functionalized Polymer

It has been found, according to the invention, that the functionalizedpolymers having a relatively high degree of functionalization areobtained when the living anion of block A is first reacted withcompounds, such as 1,1-diphenylethylene, carrying sterically hinderinggroups and the product obtained is reacted with a difunctional orpolyfunctional compound, such as trimellitic anhydride chloride. Thedegree of functionalization, which can be determined by IR spectroscopyor titration is preferably greater than 85%, particularly preferably atleast 90%, in this procedure.

In contrast to the indirect functionalization route described by Park,Barlow and Paul, it is possible to dispense with the use of ethyleneoxide, which is toxicologically unsafe. In contrast, the diphenylethylene used according to the invention is toxicologically safe.

A functionalized polymer as described above can be prepared by a processin which

a) vinylaromatic monomers are subjected to anionic polymerization togive a first living polymer of the formula A⁻ containing a Block A,

b) the first living polymer is reacted with a compound having stericallyhindering groups to give a second living polymer of the formula A—Z^(⊖)and

c) the second living polymer is reacted with a difunctional orpolyfunctional compound to give a polymer of the formula A—Z—X, theabbreviations used here having the same meanings as in the polymerclaims.

Anionic polymerization processes for the preparation of block A aredescribed in detail, for example, in U.S. Pat. No. 3,251,905, 3,390,207,3,598,887 and 4,219,627. Suitable initiators for the polymerization areorgano-alkali metal compounds, preferably lithium alkyls, eg.methyllithium, ethyllithium, n-butyllithium, sec-butyllithium orisopropyllithium. n-Butyllithium or sec-butyllithium is particularlypreferably used.

The preparation of other mono- or bifunctional anionic polymers is alsoknown and has been described, inter alia, in EP 0 303 177, EP 0 295 675,U.S. Pat. No. 4,950,721, DE 36 39 569 and DE 35 37 771.

Particularly suitable solvents for the anionic polymerization for thepreparation of novel functionalized polymers are straight-chained orbranched aliphatic hydrocarbons, eg. n-octane or n-hexane, andunsubstituted or substituted cycloaliphatic and aromatic hydrocarbons,eg. cyclohexane, methylcyclohexane, toluene or benzene, and any desiredmixture of the aliphatic, cycloaliphatic and aromatic hydrocarbons.Cyclohexane is preferably used as the solvent.

Other suitable solvent components are ethers, such as tetrahydrofuran ordiethyl ether, and tertiary amines, eg. tetramethylethylenediamine orpyridine, in concentrations of from 0.01 to 20, preferably from 0.01 to2, % by weight. Tetrahydrofuran is preferred.

All starting materials must be freed from oxygen-active and proticimpurities, this being possible, for example, by bringing into contactwith metal organyls or by adsorptive purification, for example withcalcium hydride. The polymerization is preferably carried out underinert gas conditions of from −100 to +120° C., preferably from −80 to+80° C.

According to an embodiment of the present invention, novel polymers canbe prepared by first producing the parent structure

A—Li

as a living polymer in a manner known per se by anionic polymerization,preferably with the use of lithium initiators, in particular analkyllithium, particularly preferably n-butyllithium or secondarybutyllithium. This living polymer is then reacted in a second stage witha compound of the formula

with the preparation of a second living polymer.

This further living polymer is finally reacted in a further stage with adifunctional or polyfunctional compound which introduces afunctionalized basic building block X. One functional group permitscovalent bonding of the basic building block X to Z, and at least onefurther functional group ensures the functionalization of the basicbuilding block and hence of the polymer. If, according to the invention,the difunctional or polyfunctional compound has, for example, a hydroxylgroup or a halogen atom, preferably a chlorine atom, preferably in anacid group or acyl chloride group, as a functional group which permitsbonding to the basic building block Z, a halide ion or an OH⁻ ion iseliminated with formation of a covalent bond between the basic buildingblock Z and the functionalized basic building block X. The unchargedfunctionalized polymer of the invention is formed, the functionalizationof which is as described above.

The individual stages of the novel process are preferably carried outunder the following conditions:

(a) The polymerization of the vinylaromatic compound with a lithiuminitiator is carried out at from −100 to 100° C., preferably from −20 to80° C.

(b) The reaction of the living polymer with CHR═CAryl₂ is likewisecarried out at from −100 to 100° C., preferably from −20 to 80° C.

(c) The introduction of the functional group into the further livingpolymer with elimination of the lithium is carried out at from −100 to50° C., preferably from −20 to 30° C.

In order to isolate the polymer, the polymerization mixture can beeither directly heated for drying or treated with steam by knownmethods, the solvent being distilled off. It may also be precipitated inan excess of a non-solvent, eg. ethanol, and separated off mechanicallyand dried or worked up by devolatilization in an extruder.

The reaction mixture is worked up, for example, by precipitation of thefunctionalized polymer with petroleum ether, filtration under suctionand drying of the precipitate.

According to an embodiment of the invention, the functionalized polymerhas a block A of vinylaromatic monomers which is compatible withpolyphenylene ether and polystyrene. The compatibility of two polymercomponents is understood in general as meaning the miscibility of thecomponents or the tendency of one polymer to dissolve in the otherpolymer component (cf. B. Vollmert, Grundriβ der MakromolekularenChemie, Volume IV, page 222 et seq., E. Vollmert Verlag, 1979). Twopolymers are all the more compatible the smaller the difference betweentheir solubility parameters. Such parameters and the enthalpy of mixingcannot be determined in a standard manner for all polymers, so that thesolubility can be determined only indirectly, for example bytorsion/vibration or DTA measurements. Examples of preferredvinylaromatic polymers compatible with polyphenylene ethers are given inthe monograph by O. Olabisi, Polymer-Polymer Miscibility, 1979, pages224 to 330 and 245. The functionalized basic building block X is capableof forming a bond with reinforcing agents, such as glass fibers orsilanized glass fibers, in order to bind these firmly. Consequently, thefunctionalized polymer can be used in polyphenylene ether/polystyreneblends, which may contain reinforcing agents, and can be used for thepreparation of unreinforced or reinforced thermoplastic moldingmaterials.

Thermoplastic Molding Materials Containing Polyphenylene Ether

We have found that the objects of the present invention are achieved bythe thermoplastic molding material described in the claims, reinforcedaccording to an embodiment and containing polyphenylene ether. Saidmolding material contains

(a) from 0.1 to 20% by weight of at least one functionalized polymer, asdefined in any of the polymer claims,

(b) from 1 to 98.9% by weight of at least polyphenylene ether,

(c) from 1 to 98.9% by weight of at least one vinylaromatic polymer,

(d) from 0 to 50% by weight of at least one reinforcing agent and

(e) from 0 to 60% by weight of further additives and/or processingassistants,

the amounts of components (a) to (e) together summing to 100% by weight.

Preferably, novel, unreinforced or reinforced, thermoplastic moldingmaterials contain 0.2-15, in particular 0.5-10%, by weight of component(a), 1-97.9, particularly preferably 20-89.9, in particular 35-79.5%, byweight of component (b), 1-97.9, particularly preferably 5-60, inparticular 10-45%, by weight of component (c), 1-50, particularlypreferably 5-45, in particular 10-40%, by weight of component (d) and0-30, in particular 0-20%, by weight of component (e).

The amounts of components (a)-(e) together always sum to 100% by weight.

The individual components are described in more detail below.

Polyphenylene Ether of Component (b)

The polyphenylene ether of component (b) is present in the novelreinforced thermoplastic molding materials in an amount of from 1 to98.9, preferably from 1 to 97.9, particularly preferably from 20 to89.9, in particular from 40 to 79.5%, by weight, based on the reinforcedthermoplastic molding materials. The polyphenylene ethers (b) containedin the novel molding materials are known per se. They are prepared byconventional methods by oxidative coupling of phenols disubstituted inthe ortho position by alkyl, alkoxy, chlorine or bromine (cf. U.S. Pat.No. 3,661,848, 3,378,505, 3,306,874, 3,306,875 and 3,639,656). The alkylor alkoxy groups, which are preferably of 1 to 4 carbon atoms butcontain no alpha tertiary hydrogen atom, may in turn be substituted bychlorine or bromine. Examples of suitable polyphenylene ethers arepoly-2,6-diethyl-1,4-phenylene ether,poly-2-methyl-6-ethyl-1,4-phenylene ether,poly-2-methyl-6-propyl-1,4-phenylene ether,poly-2,6-dipropyl-1,4-phenylene ether,poly-2-ethyl-6-propyl-1,4-phenylene ether,poly-2,6-dichloro-1,4-phenylene ether and poly-2,6-dibromo-1,4-phenyleneether and copolymers such as those which contain 2,3,6-trimethylphenol,as well as polymer blends. Poly-2,6-dimethyl-1,4-phenylene ether ispreferred. The polyphenylene ethers generally have a relative viscosityof from 0.3 to 0.7 dl/g, measured in 1% strength by weight solution inchloroform at 25° C.

Preferably used polyphenylene ethers are those which are compatible withvinylaromatic polymers, i.e. completely or very substantially soluble inthese polymers (cf. A. Noshay, Block Copolymers, pages 8 to 10, AcademicPress, 1977, and O. Olabisi, Polymer-Polymer Miscibility, 1979, pages117 to 189).

Graft copolymers, of polyphenylene ethers and vinylaromatic polymers,such as styrene, alpha-methylstyrene, vinyltoluene and chlorostyrene mayalso be used as polyphenylene ether component (b).

For the purposes of the present invention, modified polyphenylene ethersmay be used, as disclosed, for example, in WO 86/2086, WO 87/0540, EP-A222 246, EP-A 223 116 and EP-A 254 048.

Vinylaromatic Polymers of Component (c)

The vinylaromatic polymers are used, according to the invention, inamounts of from 1 to 98.9, preferably from 1 to 97.9, particularlypreferably from 5 to 60, in particular from 10 to 45, % by weight, basedon the reinforced thermoplastic molding material.

Vinylaromatic polymers, in particular polystyrenes, of component (c) areknown per se, for example from EP-A-0 319 833.

Examples of suitable vinylaromatic polymers are all conventional homo-and copolymers of styrene. Usually, the weight average molecular weights(M_(W)) of the commonly used styrene polymers are from 150,000 to300,000. Suitable styrene polymers are prepared predominantly fromstyrene, as well as from styrenes substituted by C₁-C₄-alkyl on thenucleus or side chain, such as alpha-methylstyrene or p-methylstyrene,by the known mass, solution or suspension methods (cf. UllmannsEnzyklopädie der technischen Chemie, Volume 19, pages 265 to 272, VerlagChemie, Weinheim 1980).

The vinylaromatic polymers of component (c) may also be toughened byadmixing small amounts, preferably from 2 to 20% by weight, based on thestyrene polymer, of an acrylate rubber or of a polymer of a conjugateddiene, such as butadiene or isoprene. The diene polymers may bepartially or completely hydrogenated. The rubber and the diene polymershould have a glass transition temperature of less than 0° C., measuredaccording to K. H. Illers and H. Breuer, Kolloidzeitschrift 176 (1961),page 100. Conventional rubbers such as polybutadiene rubber, acrylaterubber, styrene/butadiene rubber, hydrogenated styrene/butadiene rubber,acrylonitrile/butadiene rubber, polyisoprene rubber, ionomers,styrene/butadiene block copolymers, including AB, ABA and ABAB taperedblock copolymers, star block copolymers and the like, similar isopreneblock copolymers and in particular (partially) hydrogenated blockcopolymers, as disclosed per se in EP-A-62 283, are suitable. Suchsynthetic rubbers are familiar to persons skilled in the art and aresummarized, together with the unsuitable EPDM rubbers, in UllmannsEnzyklopädie der technischen Chemie, 4th edition, Volume 13, pages 595to 634, Verlag Chemie GmbH, 1977.

The toughening can also be achieved in a preferred manner by preparingthe styrene polymers in the presence of relatively small amounts, eg.from 2 to 20% by weight, based on the styrene polymer, of an elastomericpolymer based on a conjugated diene, if necessary of an acrylate rubber(HIPS). Elastomeric polymers based on butadiene, eg. styrene/butadienepolymers, polybutadiene and also butadiene/styrene block copolymers, aresuitable. These styrene polymers toughened in a specific manner arefamiliar from literature and practice to a person skilled in the art sothat further explanation appears superfluous at this point (cf. UllmannsEnzyklopädie der technischen Chemie, 4th edition, Volume 19, pages 272to 295, Verlag Chemie GmbH, 1980).

Suitable high impact polystyrenes are described, for example, in DE 3118 629 A1, as are processes for their preparation.

Reinforcing Agents of Component (d)

According to an embodiment of the invention, the polyphenyleneether-containing molding materials may be free of reinforcing agents.

According to a further embodiment of the invention, however, thepolyphenylene ether-containing molding materials contain a reinforcingagent. This embodiment is described below.

The reinforcing agents are used, according to the invention, in amountsof from 1 to 50, preferably from 5 to 45, in particular from 10 to 40, %by weight, based on the reinforced thermoplastic molding material.

The novel molding materials contain, as component (d), conventionalreinforcing materials, such as glass fibers, glass beads, mineralfibers, alumina fibers, carbon fibers, potassium titanate whiskers oraramid fibers. Carbon fibers, potassium titanate whiskers, aramid fibersand glass fibers are preferred, in particular glass fibers.

The glass fibers may comprise E, A or C glass. Their diameter is ingeneral from 6 to 20 μm. Both rovings and chopped glass fibers having alength of from I to 10 mm, preferably from 3 to 6 mm, or milled glassfibers having a length of from 0.05 to 1.5 mm may be used.

According to an embodiment of the present invention, the reinforcingagents of component (d) are untreated.

According to a further preferred embodiment of the invention, thereinforcing agents of component (d) are coated or sized. This coat orsize covers the reinforcing agents of component (d), in particular theglass fibers, preferably uniformly over the entire surface.

According to an embodiment of the invention, the coat or size comprisesa silane compound. Suitable silane compounds are those of the generalformula

(X—CH₂)_(n))_(K)—Si—(O—C_(m)H_(2m+1))_(4-K)

where

n is an integer from 2 to 10, preferably 3 or 4,

m is an integer from 1 to 5, preferably 1 or 2

K is an integer from 1 to 3, preferably 1.

Preferred silane compounds are aminopropyltrimethoxysilane,aminobutyltrimethoxysilane, aminopropyltriethoxysilane,aminobutyltriethoxysilane and the corresponding silanes which containglycidyl as substituent X.

The silane compounds are used for surface coating in general in amountsof from 0.05 to 5, preferably from 0.5 to 1.5, in particular from 0.8 to1, % by weight (based on the reinforcing agents of component (d)).

The coated or sized reinforcing agents of component (d), preferably theglass fibers coated or sized as above, can be particularly readilyreacted with the functionalized polymer of component (a). This resultsin a strong bond between the functionalized polymer of component (a) andthe reinforcing agent (d), in particular the glass fibers. Since thepolymer block A of the functionalized polymer is compatible with thepolyphenylene ether of component (b) and the vinylaromatic polymer ofcomponent (c), the reinforcing agents of component (d) are thoroughlydistributed in the novel molding materials and intimately bondedtherewith, which leads to improved tensile strength and a high modulusof elasticity.

Additives and Processing Assistants of Component (e)

The conventional additives and/or processing assistants used ascomponent (e) are employed in amounts from 0 to 60, preferably from 0 to30, in particular from 0 to 20, % by weight, based on the reinforcedthermoplastic molding material.

Particularly suitable conventional additives and processing assistantsare particulate fillers, antioxidants, flameproofing agents,conventional heat and light stabilizers, lubricants and mold releaseagents, colorants, dyes, plasticizers and pigments in conventionalamounts. Polymers other than the stated ones, for examplevinylaromatic-based polymers, polyamides as described, for example,below as component (f) and/or rubbers, may be added to the novelreinforced molding materials.

Particulate fillers as constituents of component (e) are preferablyselected from the following group: amorphous silica, magnesiumcarbonate, powdered quartz, mica, talc, feldspar, wollastonite andkaolin, in particular calcined kaolin.

Preferred combinations of components (d) and (e) are, for example, 20%by weight of glass fibers with 15% by weight of wollastonite, and 15% byweight of glass fibers with 15% by weight of wollastonite. The statedpercentages by weight are based in each case on the total components (a)to (e).

Finally, other preferred reinforced thermoplastic molding materials arethose which contain, as parts of component (e), flameproofing agentsselected from the following group: polyhalobiphenyl, polyhalodiphenylether, polyhalophthalic acid and derivatives thereof,polyhalooligocarbonates, polyhalopolycarbonates and phosphoruscompounds.

Examples of flameproofing agents are polymers of 2,6,2′,6′-tetrabromobisphenol A, of tetrabromophthalic acid, of2,6-dibromophenol and of 2,4,6-tribromophenol and of derivativesthereof.

A preferred flameproofing agent is elemental phosphorous. As a rule, theelemental phosphorus may be desensitized or coated with, for example,polyurethanes or aminoplasts. Masterbatches of red phosphorus, forexample in a polyamide, elastomer or polyolefin, are also suitable.Combinations of elemental phosphorus with 1,2,3,4,7,8,9,10,13,13,14,14-dodecachloro-1,4,4a,5,6,6a,7,10,10a,11,12,12a-dodecahydro-1,4:7,10-dimethanodibenzo(a,e)cyclooctaneand, if required, a synergistic agent, eg. antimony trioxide, areparticularly preferred.

Phosphorus compounds, such as organic phosphates, phosphonates,phosphinates, phosphine oxides, phosphines or phosphites, are alsopreferred. Examples are triphenylphosphine oxide, triphenyl phosphateand resorcinolbistriphenylphosphine oxide. This may be used alone or asa mixture with hexabromobenzine or a chlorinated biphenyl and, ifdesired, antimony oxide.

Typical of the preferred phosphorus compounds which may be usedaccording to the present invention are those of the general formula

where Q are identical or different radicals, hydrocarbon radicals, suchas alkyl, cycloalkyl, aryl, alkyl-substituted aryl or aryl-substitutedalkyl, or halogen, hydrogen or a combination thereof, provided that atleast one of the radicals Q is aryl.

Examples of such suitable phosphates are phenyl bisdodecyl phosphate,phenyl bisneopentyl phosphate, phenyl ethylene hydrogen phosphate,phenyl bis(3,5,5′-trimethylhexyl) phosphate, ethyl diphenyl phosphate,2-ethylhexyl di(p-tolyl) phosphate, bis(2-ethylhexyl) phenyl phosphate,tri(nonylphenyl) phosphate, phenyl methyl hydrogen phosphate, didodecylp-tolyl phosphate, tricresyl phosphate, triphenyl phosphate, dibutylphenyl phosphate and diphenyl hydrogen phosphate. The preferredphosphates are those in which each Q is aryl. The most preferablephosphate is triphenyl phosphate, triphenyl phosphine oxide and phenylbistriphenyl phosphine oxide also being particularly preferred.

Furthermore, the combination of triphenyl phosphate withhexabromobenzene and antimony trioxide is preferred.

Other suitable flameproofing agents are compounds which containphosphorus-nitrogen bonds, such as phosphonitrile chloride, phosphoricester amides, phosphoric ester amines, phosphoramides, phosphonamides,phosphinamides, tris(aziridinyl)phosphine oxide ortetrakis-(hydroxymethyl)phosphonium chloride. These flame-retardantadditives are for the most part commercially available.

Other suitable flameproofing agents are hydroxides of magnesium, which,if required, are coated with silane compounds.

Further halogen-containing flameproofing agents are tetrabromobenzene,hexachlorobenzene and hexabromobenzene and halogenated polystyrenes andpolyphenylene ethers.

The halogenated phthalimides described in DE 19 46 924 may also be used.Among these, N,N′-ethylenebistetrabromophthalimide has becomeparticularly important.

Antioxidants and heat stabilizers which may be added to thethermoplastic materials according to the invention are, for example,halides of metals of the first group of the Periodic Table, for examplesodium, potassium or lithium halides, if necessary in combination withcopper(I) halides, for example chlorides, bromides or iodides. Zincfluoride and zinc chloride may also be used. Sterically hinderedphenols, hydroquinones, substituted members of this group and mixturesof these compounds may also be used, preferably in concentrations of upto 1% by weight, based on the weight of the mixture.

Examples of UV stabilizers are various substituted resorcinols,salicylates, benzotriazoles and benzophenones, which are generally usedin amounts of up to 2% by weight.

Materials for increasing the shielding against electromagnetic waves,such as metal flakes, metal powders, metal fibers or metal-coatedfillers, may also be present.

Lubricants and mold release agents, which are added to the thermoplasticmaterial as a rule in amounts of up to 1% by weight, are stearic acid,stearyl alcohol, alkyl stearates and stearamides and esters ofpentaerythritol with long-chain fatty acids.

The additives include stabilizers which prevent the decomposition of redphosphorus in the presence of moisture and atmospheric oxygen. Examplesare compounds of cadmium, of zinc, of aluminum, of silver, of iron, ofcopper, of antimony, of tin, of magnesium, of manganese, of vanadium, ofboron, of aluminum and of titanium. Particularly suitable compounds are,for example, oxides of the stated metals, and carbonates or basiccarbonates, hydroxides and salts of organic or inorganic acids, such asacetates or phosphates or hydrogen phosphates and sulfates.

The novel molding materials may contain, as a preferred stabilizer, atleast one phosphorus-containing inorganic acid or a derivative thereofin an amount of up to 1000, preferably from 30 to 200, in particularfrom 50 to 130, ppm, based on the phosphorus content of the compounds.

Preferred acids are hydrophosphorous acid, phosphorous acid andphosphoric acid and salts thereof with alkali metals, sodium andpotassium being particularly preferred. Organic derivatives of theseacids are to be understood as meaning preferably ester derivatives ofabovementioned acids with fatty acids, the fatty acids being of 12 to44, preferably 22 to 40, carbon atoms. Examples are stearic acid,behenic acid, palmitic acid and montanic acid.

Various substituted resorcinols, salicylates, benzotriazoles andbenzophenones may be mentioned as UV stabilizers, which are used ingeneral in amounts of up to 2% by weight, based on the molding material.

Furthermore, organic dyes, such as nigrosine, and pigments, such astitanium dioxide, cadmium sulfide, cadmium selenide, phthalocyanines,ultramarine blue and carbon black, may be added as colorants.

Lubricants and mold release agents, which are usually used in amounts ofup to 1% by weight, are preferably long-chain fatty acids (eg. stearicacid or behenic acid), salts thereof (eg. calcium or zinc stearate) orester derivatives (eg. stearyl stearate or pentaerythrityltetrastearate) and amide derivatives (eg. ethylene bisstearylamide).

Examples of plasticizers are dioctyl phthalate, dibenzyl phthalate,butyl benzyl phthalate, hydrocarbon oils, N-(n-butyl)benzenesulfonamideand o- and p-tolylethylsulfonamide.

Rubber

A rubber is defined as a polymer which increases the impact strength ofpolyphenylene ether and/or of polyamides. In specific cases, the rubberused as a component differs from the other components (a), (b), (c), (d)and (f) used. Suitable rubbers which increase the toughness ofpolyphenylene ethers are:

polyoctenylenes, graft rubbers having a crosslinked, elastomeric core,which is derived, for example, from butadiene, isoprene or alkylacrylates, and a graft shell of polystyrene, and furthermore copolymersof ethylene and acrylates or methacrylates and the ethylene/propylene(EP) and ethylene/propylene/diene (EPDM) rubbers, and the EP or EPDMrubbers grafted with styrene.

Block copolymers having up to six, preferably up to four, identical ordifferent blocks, which may be bonded either linearly or in astar-shaped manner (radio block copolymers) may also be used.

Blends of block copolymers having different structures, for exampleblends of two- and three-block copolymers or of hydrogenated andunhydrogenated block copolymers, may also be used.

Polymers toughened by the addition of the stated rubbers are known perse and are described in the literature. Merely by way of example,reference is made here to U.S. Pat. No. 4,085,163, U.S. Pat. No. 41,103,U.S. Pat. No. 3,149,182, U.S. Pat. No. 3,231,635 and U.S. Pat. No.3,462,162. Appropriate products are also commercially available.

Rubbers which increase the toughness of polyamides generally have twoessential features: they contain an elastomeric fraction which has aglass transition temperature of less than −10° C., preferably less than−30° C., and they contain at least one functional group capable ofreacting with the polyamide. Suitable functional groups are, forexample, carboxyl, carboxylic anhydride, carboxylic ester, carboxamido,carboximido, amino, hydroxyl, epoxy, urethane and oxazoline groups.

Examples of rubbers which increase the toughness of polyamides are:

EP and EPDM rubbers which have been grafted with the abovementionedfunctional groups. Suitable graft reagents are, for example, maleicanhydride, itaconic acid, acrylic acid, glycidyl acrylate and glycidylmethacrylate. These monomers may be grafted onto the polymer in the meltor in solution, in the presence or absence of a free radical initiator,such as cumyl hydroperoxide.

Copolymers of α-olefins may also be mentioned. The α-olefins are usuallymonomers of 2 to 8 carbon atoms, preferably ethylene and propylene.Alkyl acrylates and alkyl methacrylates which are derived from alcoholsof 1 to 8 carbon atoms, preferably from ethanol, butanol orethylhexanol, and reactive comonomers, such as acrylic acid, methacrylicacid, maleic acid, maleic anhydride or glycidyl (meth)acrylate, andfurthermore vinyl esters, in particular vinyl acetate, have provensuitable comonomers. Mixtures of different comonomers may also be used.Copolymers of ethylene with ethyl or butyl acrylate and acrylic acidand/or maleic anhydride have proven particularly suitable.

The copolymers can be prepared by a high pressure process at from 400 to4500 bar or by grafting the comonomers on the poly-α-olefin. Theα-olefin content of the copolymer is in general from 99.95 to 55% byweight.

A further group of suitable elastomers comprises core-shell graftrubbers. These are graft rubbers which are prepared in emulsion andcomprise at least one hard and one soft component. A hard component isusually understood as meaning a polymer having a glass transitiontemperature of at least 25° C., and a soft component as meaning apolymer having a glass transition temperature of not more than 0° C.These products have a structure comprising a core and at least oneshell, the structure being determined by the order of addition of themonomers. The soft components are derived in general from butadiene,isoprene, alkyl acrylates or alkyl methacrylates and, if required,further comonomers. Examples of suitable comonomers here are styrene,acrylonitrile and crosslinking or graft-linking monomers having morethan one polymerizable double bond, such as diallyl phthalate,divinylbenzene, butanedioldiacrylate or triallyl (iso)cyanurate. Thehard components are derived in general from styrene, α-methylstyrene andcopolymers thereof, preferred comonomers here being acrylonitrile,methacrylonitrile and methyl methacrylate.

Preferred core-shell graft rubbers contain a soft core and a hard shellor a hard core, a first soft shell and at least one further hard shell.Functional groups, such as carbonyl, carboxyl, anhydride, amido, imido,carboxylic ester, amino, hydroxyl, epoxy, oxazoline, urethane, urea,lactam or halobenzyl groups, are incorporated here preferably by addingsuitable functionalized monomers during the polymerization of the fmalshell. Suitable functionalized monomers are, for example, maleic acid,maleic anhydride, mono- or diesters of maleic acid, tert-butyl(meth)acrylate, acrylic acid, glycidyl (meth)acrylate and vinyloxazoline. The amount of monomers having functional groups is in generalfrom 0.1 to 25, preferably from 0.25 to 15, % by weight, based on thetotal weight of the core-shell graft rubbers. The weight ratio of softto hard components is in general from 1:9 to 9:1, preferably from 3:7 to8:2.

Such rubbers which increase the toughness of polyamides are known per seand are described, for example, in EP 0 208 187.

Blends of different rubbers may of course also be used.

Preparation of the Thermoplastic Molding Materials

The novel thermoplastic molding materials, reinforced according to anembodiment, can be prepared by processes known per se, by mixing thestarting components in a conventional mixing apparatus, such as anextruder, preferably a twin-screw extruder, a Brabender mill or aBanbury mill, and then extruding the mixture. After extrusion, theextrudate is cooled and comminuted.

Thorough mixing is advantageous for obtaining a very homogeneous moldingmaterial. The novel molding materials are usually prepared as describedbelow:

The components (a) to (c), according to an embodiment (d), and, ifdesired (e) are generally melted and mixed at from 200 to 320° C.,preferably from 250 to 300° C., in particular 280° C., in an extruder,roll mill or kneader, preferably a twin-screw extruder, during aresidence time of from 0.5 to 10 minutes. Solutions of components (b),(a) and (c) or partial mixtures thereof may also be prepared and mixed,the solvents then removed by devolatilization and, according to anembodiment of the invention, the mixture is mixed with the reinforcingagent (d) and, if required, further additives (e) and compounded again.According to this embodiment, mixing of the components (a), (b) and (c)is preferably carried out in the presence, or with the addition, of thereinforcing agent (d). It is also possible to premix some or all ofcomponent (a) with at least one other component or with the reinforcingagent (d).

In a preferred process for the preparation of the thermoplastic moldingmaterials, which are reinforced according to an embodiment of theinvention, the components (a), (b), (c), (d) and, if required, (e) aremixed in an extruder at from 200 to 320° C., component (d) being coatedwith component (a) and the coated component (d) being introduced into anorifice of an extruder and being mixed in the extruder with the moltencomponents (b) and (c) and, if desired, (e).

The novel molding material is particularly preferably prepared by thefollowing method:

The functionalized polymer of component (a) is melted or dissolved andadded directly to the glass roving of the reinforcing agent (d) or saidroving is impregnated with the dispersion or solution and introducedtogether with the glass fibers into an orifice of the extruder andcombined with the melt of components (b) and (c) and, if desired, (e),if required the solvent or dispersant being evaporated or being strippedoff under reduced pressure.

Novel materials can also be prepared by a pultrusion process, asdescribed in EP-A-56 703. In this process, the glass roving isimpregnated with the polymer material and then cooled and comminuted.The glass fiber length in this case is identical to the granule lengthand is from 3 to 20 mm.

The residence times are in general from 0.5 to 50, preferably from 4 to24, hours.

Thereafter, moldings can be produced from the molding materials, forexample by means of conventional apparatuses for blow molding, profileextrusion and pipe extrusion or injection molding.

The thermoplastic molding materials prepared in this manner have abalanced property profile, in particular very good tensile strength andflowability in combination with good rigidity, in particular when thereinforcing agent (d) is used.

According to the invention, moldings, in particular injection moldedarticles, fibers, films and foils, consisting essentially of the moldingmaterials described are therefore also provided.

Thermoplastic Molding Materials Containing Polyamide

We have found that the objects of the present invention are achieved bythe thermoplastic molding material which is described in the claims,contains polyamide and, according to an embodiment, is reinforced.

Said molding material contains

(a) from 0.1 to 40% by weight of at least one functionalized polymer, asdefined in any of the polymer claims,

(b) from 1 to 98.9% by weight of at least one polyphenylene ether,

(c) from 0 to 97.9% by weight of at least one vinylaromatic polymer,

(d) from 0 to 50% by weight of at least one reinforcing agent,

(e) from 0 to 60% by weight of further additives and/or processingassistants and

(f) from 1 to 98.9% by weight of at least one polyamide,

the amounts of the components (a) to (f) together summing to 100% byweight.

Preferably, these novel thermoplastic molding materials contain 0.2-35,in particular 5-20, % by weight of component (a), 1-97.9, particularlypreferably 20-80, in particular 25-50, % by weight of component (b),0-50, in particular 0-30, % by weight of component (c), 1-50,particularly preferably 445, in particular 10-40, % by weight ofcomponent (d), 1-97.9, particularly preferably 0-30, in particular 0-20,% by weight of component (e) and 1-97.9, particularly preferably 15-75,in particular 30-60, % by weight of component (f).

The amounts of components (a) to (f) together always sum to 100% byweight.

The components (a) to (e) are as described above and are used in theamounts stated here.

The component (f) is described in more detail below.

Polyamides of Component (f)

Polyamides of component (f) may be thermoplastic semicrystallinepolyamides. Semicrystalline polyamides are as a rule linear.

Such polyamides can be prepared, for example, by condensation ofequimolar amounts of a saturated dicarboxylic acid of 4 to 12 carbonatoms with a diamine of 4 to 14 carbon atoms or by condensation ofω-aminocarboxylic acids or polyaddition of lactams.

Examples of suitable polyamides are polyhexamethyleneadipamide,polyhexamethyleneazelaamide, polyhexamethylenesebacamide,polyhexamethylenedodecanediamide, polytetramethyleneadipamide and thepolyamides obtained by ring cleavage of lactams, such as polycaprolactamand polylaurolactam.

A polyamide (f) from the following group is particularly preferred:polytetramethyleneadipamide, polyhexamethyleneadipamide,polyhexamethylenesebacamide, polycaprolactam, copolyamides ofterephthalic acid, hexamethylenediamine and ε-caprolactam, andcopolyamides of terephthalic acid, isophthalic acid,hexamethylenediamine and, if desired, adipic acid, the amount ofterephthalic acid and of hexamethylenediamine together being less than50% by weight, based on the copolyamide. From this group, thepolyhexamethyleneadipamide and polycaprolactam are particularlypreferred. Mixtures of different polyamides may also be used.

In preferred thermoplastic molding materials, the difference between theamounts of terminal NH₂ and COOH groups in the polyamides used is lessthan 70, in particular less than 40, mmol/kg. Differences in terminalgroups of from 10 to 30 mmol/kg are particularly preferred. These valuesare determined by known methods.

Polyamides having a viscosity number of from 40 to 250, in particularfrom 40 to 150, ml/g, measured according to DIN 53426, are preferablyused.

Low molecular weight polyamides or polyamide prepolymers can beprepared, for example, by the processes described in EP 0 129 195, EP 0129 196 and EP 0 299 444. Further batchwise and continuous preparationprocesses are known to a person skilled in the art.

In a preferred procedure, the low molecular weight polyamide is passedin molten form through a discharge zone with simultaneous removal of theresidual water contained in the melt. Suitable discharge zones are, forexample, devolatilization extruders. The melt freed from water in thismanner is then extruded and the extrudates granulated. The granulesobtained are melted at about 20° C. above their melting point (in thecase of polyhexamethyleneadipamide at about 280° C.), preferably in atwin-screw extruder, mixed with the functionalized polymer, thepolyphenylene ether and, if required, the rubber, the additives orprocessing assistants and extruded, and the extrudate is cooled andgranulated.

The novel thermoplastic molding materials which contain polyamide may befree of vinylaromatic polymers. According to an embodiment of theinvention, however, they may contain 0-97.9, preferably 0-50, inparticular 0-35, % by weight of at least one vinylaromatic polymer(component (c)). They may thus be polyphenylene ether/polyamide blendsor polyphenylene ether/polyamide/vinylaromatic blends.

The novel thermoplastic molding materials may be prepared by processesknown per se, as described above for the reinforced thermoplasticmolding materials, except that in this case a polyamide is used asfurther component (f), and component (c) can be dispensed with accordingto an embodiment.

According to an embodiment of the invention, the components (a) to (e)are mixed, preferably in an extruder, and component (f) is then meteredinto the mixture of components (a) to (e), preferably in heated form ina side extruder. Any reinforcing agents (d) present, which, according toan embodiment of the invention, may be precoated with (a), can beincorporated into the first mixture or metered in together with thepolyamide (f).

The thermoplastic molding materials thus prepared have a balancedproperty profile, in particular a very good toughness/rigidity ratio, inparticular when the reinforcing agent (d) is used.

According to the invention, moldings, fibers, films and foils of thethermoplastic molding materials are also provided and can be produced bythe process described below.

The Examples which follow illustrate the invention with reference toreinforced molding materials.

EXAMPLES Example 1

The functionalized styrene polymer component (a) having an averagepolystyrene molecular weight of 30,000 and terminal anhydride group (a1)was used. A second functionalized component (a) had an averagepolystyrene molecular weight of 90,000 and a terminal anhydride group(a2). A third functionalized component (a) had an average polystyrenemolecular weight of 30,000 and a terminal primary amino group (a3). Thestyrene polymers were prepared as described below.

The polymer (a1) was prepared as follows: 3200 ml of dry cyclohexane and0.3 ml of 1,1-diphenylethylene were initially taken in a blanketed 6 1stirred kettle. Thereafter, 1.5 mol of secondary butyllithium solution(in 92/8 cyclohexane/isopentane) were added until a red color persisted.A further 16 ml of butyllithium solution were then added. Thereafter,800 ml of highly pure styrene were added dropwise at 60° C. in thecourse of 2 hours. After stirring had been carried out for a furtherhour, 7 ml of 1,1-diphenylethylene were added, after which stirring wascontinued for a further half hour and finally the mixture was cooled to20° C. In the meantime, 30 g of trimellitic anhydride chloride in 300 mlof dry tetrahydrofuran were initially taken in a further blanketed 6 1stirred kettle and cooled to 0C. The content of the first stirred kettlewas then added dropwise in the course of from 1 to 2 hours. After asubsequent reaction time of 1 hour, the resulting styrene polymer wasprecipitated with petroleum ether, filtered off under suction and dried.The anhydride-modified polymer thus prepared had an average molecularweight (GPC in CHCl₃ against polystyrene calibration standards) of30,000 (M_(n)).

The polymer (a2) was prepared in the same manner, but with 6 instead of16 ml of a 1.5 molar secondary butyllithium solution as initiator. Theaverage molecular weight of the resulting styrene polymers was 90,000(M_(n)).

The polymer (a3) was prepared in the same manner as the polymer (a1).The product was dissolved in 5 l of cyclol. 20 g of 1,4-diaminobutanewere then added and stirring was then carried out for 4 hours at 120° C.After cooling, the product was precipitated in methanol, isolated anddried. The average molecular weight of the resulting styrene polymermodified with a primary amine was 30,000 (M_(n)).

The degree of functionalization of the functionalized polymers (a1),(a2) and (a3) was determined by ¹H-NMR.

The following degrees of functionalization were obtained:

(a1) 94%

(a2) 90%

(a3) 96%

Poly-2,6-dimethyl-1,4-phenylene ether having an intrinsic viscosity of0.55 dl/g, measured at a concentration of about 1% by weight inchloroform at 25° C., was used as component (b).

Three polystyrenes were used as component (c):

(c1) is a high impact polystyrene KR2756 from BASF AG, containing 8% byweight of butadiene and having a melt flow index of 3 g/10 minutes,measured according to DIN 53735 at 200° C. and 5 kg load.

(c2) is a general purpose polystyrene 148 H from BASF AG, having thefollowing properties:

VST/B/50(ISO 306)=101° C.

MVR 200/5(ISO 1133)=4.5

(c3) is a copolymer of 95% by weight of styrene and 5% by weight oftert-butyl acrylate, having a viscosity number of 1.0 dl/g. It wasprepared by the process described in EP-A-0 319 833 for component B (cf.page 6, line 57 et seq.).

The following glass fibers were used as component (d):

A chopped glass fiber which had a mean fiber diameter of 40 μm and anaminosilane size was used as component (d1), said fiber beingobtainable, for example, under the name OCF^(R)R 44DX2 from OwensCorning Fiberglass Corp.

The chopped glass fiber 5145EC14 from Vetrotex International S.A., whichhad a diameter of 1 μm and a silane size, was used as component (d2).

Preparation of the Molding Materials

The components (a), (b), (c) and (d) were compounded using the parts byweight stated in Table 1, in all 7 examples in a twin-screw extruderoperated at 200 rpm. The temperature was 280° C. The molding materialwas granulated after extrusion and finally processed to thecorresponding moldings by injection molding method at 280° C.

The flowability (melt volume rate, MVR 250° C./21.6 kg), measuredaccording to DIN 53 735, the tensile strength, measured according to DIN53 455, and the modulus of elasticity, measured according to DIN 53 457,are shown in Table 2.

Examples 2, 3, 4 and 6 related to reinforced thermoplastic moldingmaterials which are prepared according to the invention and contain afunctionalized styrene polymer (a), and Examples 1, 5 and 7 arecomparative materials without the functionalized styrene polymer (a).

TABLE 1 Compositions (in % by weight) of the novel Examples andComparative Experiments (=*) Component a Component b Component cComponent d  1* — 35 b1 20 c1 30 d1 15 c2 2 5 a1 35 b1 20 c1 30 d1 10 c23 5 a2 35 b1 20 c1 30 d1 10 c2 4 5 a3 35 b1 20 c1 30 d1 10 c2  5* — 35b1 20 c1 30 d2 10 c2  5 c3 6 5 a1 40 b1 25 c1 20 d2 10 c2  7* — 40 b1 25c1 20 d2 15 c2

TABLE 2 Properties of the novel Examples and Comparative Experiments MVRModulus of elasticity Tensile strength [ml/10 min] [N/mm²] [N/mm²]  1*15 8600 119 2 23 9150 131 3 20 9400 138 4 22 9250 135  5* 12 8800 122 634 7150 120  7* 25 6700 108

The table shows that the novel reinforced thermoplastic moldingmaterials simultaneously have good flowability, high tensile strengthand a high modulus of elasticity in contrast to the comparativepolymers, which have poor flowability, lower tensile strength and alower modulus of elasticity.

In the molding materials according to Examples 1 to 5, an identicalcomposition of components (b) and (d) was used, while in the materialsof Comparative Examples 1 and 5 the amount of component (c) wasincreased by an amount corresponding to that of component (d) in thenovel materials according to Examples 2 to 4. Thus, the functionalizedpolystyrene was replaced by the high impact polystyrene in ComparativeExample 1 and by a styrene copolymer in Comparative Example 5. Theproperties of the materials shown in Table 2 show that the novelmaterials according to Examples 2 to 4 have considerably improvedflowability compared with the materials of Comparative Examples 1 and 5and also possess substantially improved modulus of elasticity andimproved tensile strength.

A different composition of the components (b) and (d) was used in thematerials according to Examples 6 and 7, the novel functionalizedpolystyrene of component (a) being used in Example 6 and, on the otherhand, once again a correspondingly increased amount of component (c)being used in the material according to Comparative Example 7. From theresults shown in Table 2, it is clear that the novel molding materialhas higher values for the flowability, the modulus of elasticity and thetensile strength.

The properties of the novel molding materials are thus clearly superiorto the properties of the prior art comparative materials.

Example 2

For comparison purposes, a functionalized styrene polymer component (a4)was prepared by the direct functionalization process described by Park,Barlow and Paul. This comparative polymer had the following properties:

Terminal group: Trimellitic anhydride;

Polystyrene molecular weight: 30,000;

Degree of functionalization: 63%

The degree of functionalization was determined by ¹H-NMR spectroscopy,as described by Park, Barlow and Paul.

Preparation of the Molding Materials

The components (a), (b), (c) and (d), as stated above or in Example 1,were prepared as described in Example 1, using the parts by weightstated in Table 3.

TABLE 3 Component Component a Component b Component c d  8* 5 a4 50 b130 c1 10 d1  5 c2 9 5 a2 50 b1 30 c1 10 d1  5 c2

The flowability, the tensile strength and the modulus of elasticity weredetermined as stated in Example 1 and are shown in Table 4.

TABLE 4 MVR [ml/10 Modulus of elasticity Tensile strength min] [N/mm²][N/mm²]  8* 36 5530 125 9 35 5605 135

The table shows that the thermoplastic molding material reinforcedaccording to the invention has flowability very similar to that of thecorresponding molding material prepared using the polystyrene directlyfunctionalized according to the prior art, the tensile strength and themodulus of elasticity being greater than in the case of the comparativemixture.

Example 3

For comparison purposes, functionalized styrene polymer components (a)were prepared by the indirect functionalization method described byPark, Barlow and Paul, using ethylene oxide. These comparative polymersof the functionalized styrene polymer component (a) had the followingproperties:

TABLE 5 a5* a6* a7* Terminal group anhydride anhydride primary aminePolystyrene molecular weight 30,000 90,000 30,000 Degree offunctionalization [%]    80    70    40

Trimellitic anhydride was used as the anhydride group. The primary amineused for the synthesis was 1,4-diaminobutane.

The degree of functionalization was determined by means of ¹H-NMRspectroscopy, as described by Park, Barlow and Paul.

Preparation of the Molding Materials

The components (a), (b), (c) and (d), as stated above or in Example 1,were prepared as described in Example 1, using the parts by weightstated in Table 6.

TABLE 6 Component a Component b Component c Component d 10* 5 a5* 35 b120 c1 30 d1 10 c2  2 5 a1  35 b1 20 c1 30 d1 10 c2 11* 2 a7* 33 b1 20 c130 d2 10 c2  5 c3 12 2 a3  33 b1 20 c1 30 d2 10 c2  5 c3 13* 10 a6*  40b1 25 c1 20 d2  5 c2 14 10 a2  40 b1 25 c1 20 d2  5 c2

The flowability, the tensile strength and the modulus of elasticity weredetermined as stated in Example 1 and are shown in Table 7.

TABLE 7 MVR [ml/10 Modulus of elasticity Tensile strength min] [N/mm²][N/mm²] 10* 23 9048 117  2 23 9150 131 11* 28 8700  93 12 26 8943 10213* 34 7726 121 14 34 7308 126

The table shows that the novel reinforced thermoplastic moldingmaterials have flowability identical or very similar to that of thecorresponding molding materials prepared using polystyrenes indirectlyfunctionalized according to the prior art, the tensile strength and themodulus of elasticity being greater than in the case of the comparativemixtures.

We claim:
 1. A process for preparing a functionalized polymer of theformula A—Z—X where A is a block of vinylaromatic monomers of 8 to 20carbon atoms, Z is a basic building block comprising a compound havingsterically hindering groups and X is a basic building blockfunctionalized with a terminal acid anhydride group, wherein the degreeof functionalization of the polymer is at least 65%, wherein a)vinylaromatic monomers are subjected to anionic polymerization to give afirst living polymer of the formula A⁻ containing a block A, b) thefirst living polymer is reacted with a compound having stericallyhindering groups to give a second living polymer of the formula A—Z⁻ andc) the second living polymer is reacted with a functional group of adifunctional or polyfunctional compound to give a compound of theformula A—Z—X.
 2. A process as claimed in claim 1, having one or more ofthe following features: A is a block of styrene or α-methylstyrene, Z isa basic building block of the formula

where R is a hydrogen radical or hydrogen and aryl is aryl of 6 to 10carbon atoms.
 3. A functionalized polymer of the formula A—Z—X where Ais a block of vinylaromatic monomers of 8 to 20 carbon atoms, Z is abasic building block of the formula

where R is a hydrocarbon radical or hydrogen and aryl is aryl of 6 to 10carbon atoms, and X is a basic building block, functionalized with aterminal acid anhydride group, wherein the degree of functionalizationof the polymer is at least 90%.
 4. A functionalized polymer as claimedin claim 3, wherein A is a block of styrene or α-methylstyrene. 5.Method of using of a functionalized polymer as claimed in claim 3 forthe preparation of unreinforced or reinforced, thermoplastic moldingmaterials.
 6. A thermoplastic molding material containing (a) from 0.1to 20% by weight of at least one functionalized polymer, as defined inclaim 3, (b) from 1 to 98.9% by weight of at least polyphenylene ether,(c) from 1 to 98.9% by weight of at least one vinylaromatic polymer, (d)from 0 to 50% by weight of at least one reinforcing agent and (e) from 0to 60% by weight of further additives and/or processing assistants, theamounts of components (a) to (e) together summing to 100% by weight. 7.A process for the preparation of an unreinforced or reinforced,thermoplastic molding material as claimed in claim 6, wherein thecomponents (a), (b), (c) and optionally (d) and/or (e) are mixed in anextruder at from 200 to 320° C., if required, component (d) being coatedwith component (a) and the coated component (d) being introduced into anorifice of an extruder and being mixed in the extruder with the moltencomponents (b) and (c) and, if desired, (e).
 8. A thermoplastic moldingmaterial containing (a) from 0.1 to 40% by weight of at least onefunctionalized polymer, as defined in claim 3, (b) from 1 to 98.9% byweight of at least one polyphenylene ether, (c) from 0 to 97.9% byweight of at least one vinylaromatic polymer, (d) from 0 to 50% byweight of at least one reinforcing agent, (e) from 0 to 60% by weight offurther additives or processing assistants and (f) from 1 to 98.9% byweight of at least one polyamide, the amounts of the components (a) to(f) together summing to 100% by weight.
 9. A process for the preparationof an unreinforced or reinforced thermoplastic molding material asclaimed in claim 8, wherein the components (a), (b) (f) and optionally(c), (d) and/or (e) are mixed in an extruder at from 200 to 320° C.,component (f) being introduced into an orifice of an extruder and beingmixed in the extruder with the molten components (a), (b), (c) and (e)and it being possible to mix component (d) with component (f) or withcomponents (a), (b), (c) and (e).
 10. Method of using of a thermoplasticmolding material as claimed in claim 6 for the production of moldings,fibers and foils.
 11. A molding, fiber or foil comprising a moldingmaterial as claimed in claim
 6. 12. A process as claimed in claim 1,wherein A is a block of vinylaromatic monomers of 8 to 12 carbon atoms.13. A process as claimed in claim 2, wherein R is an alkyl of 1 to 4carbon atoms or hydrogen.
 14. A functionalized polymer as claimed inclaim 3, wherein A is a block of vinylaromatic monomers of 8 to 12carbon atoms.
 15. A functionalized polymer as claimed in claim 3,wherein R is an alkyl of 1 to 4 carbon atoms or hydrogen.
 16. Afunctionalized polymer as claimed in claim 3, wherein A is a block ofstyrene or α-methylstyrene, and R is an alkyl of 1 to 4 carbon atoms orhydrogen.
 17. A thermoplastic molding material as claimed in claim 6,wherein A is a block of vinylaromatic monomers of 8 to 12 carbon atoms,and R is an alkyl of 1 to 4 carbon atoms or hydrogen.